Thermoplastic polyetherimide ester elastomers comprised of the reaction products of (a) a diol, (b) a dicarboxylic acid, (c) a high molecular weight poly(oxy alkylene)diamine, and (d) a tricarboxylic acid or its derivatives are known and are described in U.S. Pat. Nos. 4,544,734 and 4,556,708 to McCready and in U.S. Pat. No. 4,556,688 to McCready et al. These polyetherimide esters exhibit excellent stress-strain properties low tensile set, high melting temperatures, and/or excellent strength/toughness characteristics as well as superior flexibility which are especially suitable for molding and extrusion applications.
It has now been discovered that block polymers of these polyetherimide esters which contain blocks of ester units and blocks of polyetherimide ester units can be provided.